Flow-regulating valve



Oct. 9, 195

A. l.. BUssoN 2,570,317

FLOW REGULATING VALVE Filed June 18, 1945 INVENToR.

AMBROSE l.. BUSSON ATTORNEY\ Patented Oct. 9, 1951 FLOW-REGULATING VALVEAmbrose L. Busson, Detroit, Mich., assignor to Vickers Incorporated,Detroit, Mich., a, corporation of Michigan Application June 18, 1945,Serial No. 600,005

'I Claims.

This invention relates to power transmissions, particularly to those ofthe type comprising two or more fluid pressure energy translatingdevices, one of which may function as a pump and another as a uid motor.

In particular, the invention relates to an improvement in anow-regulating valve comprising an adjustable throttle and acompensating valve for maintaining a constant now across the throttlethrough which iiuid is adapted to flow at a regulated rate regardless ofload resistance.

Flow-regulating valves have an important use in hydraulic powertransmissions for driving machine tools. They serve the purpose ofproducing a reduced speed rate of the machine tool, and the machine toolmay be driven at a constant regulated rate of speed regardless of loadresistance.

In the past some difficulty was presented in preventing motor jump whenthe motor was started after interruption and in particular when amachine tool slide was moved into a feed position from rest or wherethere was a resumption of a feed movement after interruption during aslide movement. In many cases, if a feed movement was interrupted andthe operator of the slide machine tool did not back the tool away fromthe work before resuming a cut, the tool was ruined. This is due to thefact that, when ow through the flow-regulating valve is interrupted, thecompensating valve is held to the fully open position by a compensatingvalve spring. When flow is resumed after interruption, a temporary iiowof fluid above the normal regulated rate passes through thefopencompensating valve before it is able to assume normal regulatingposition. Although this is only a momentary lapse and the compensatingvalve almost immediately assumes normal regulating position, thistemporary flow of fluid above the normal regulated rate causes the motorto jump slightly before a constant regulated movement begins and ruins acutting tool.

In the past this difiiculty has been avoided by the addition of valvesincorporated in the transmission to induce a flow through theflow-regulating valve when flow to the motor was interrupted, therebyplacing the compensating valve already in a position to regulatenormally when flow to the motor was resumed. This necessitatedadditional valves, lines and fittings in the hydraulic transmission.

It is an object of this invention to provide an improved flow-regulatingvalve for use in a hydraulic transmission containing a fluid pumpandmotor which will prevent motor jump when flow is resumed through theflow-regulating valveV after interruption.

It is also an object of this invention to. provide a now-regulatingvalve which will prevent motor jump when flow is resumed'through theflow-regulating valve after interruption by preventing a flow above thenormal regulated rate before the compensating valve assumes regulatingposition.

It is also an object of this invention to incorporate in combinationwith an adjustable throttle and compensating valve, comprising aflow-regulating valve, a pressure responsive sleeve to prevent a ilow offluid above the normal regulated rate when the motor is started afterinterruption.

It is a further object of this invention to provide an improvedflow-regulating valve which will prevent motor jump when ilow is resumedthrough the flow-regulating valve after interruption which may beeconomically manufactured, simple in operation, and which avoids theaddition to the hydraulic transmission of extra valves, lines orfittings.

Further objects and advantages of the present invention will be apparentfrom 'the following description, reference being had tothe accompanyingdrawing wherein a preferred form of the present invention is clearlyshown.

In the drawing:

Figure 1 is a diagrammatic view of a hydraulic power transmission systemincorporating a, preferred form of the present invention in the closedposition.

Figure 2 is a diagrammatic view of the same hydraulic power transmissionsystem shown in- Figure 1 showing the parts in a different position.

Referring now to Figure 1, there is shown a pump I0 which may be drivenby an electric motor, not shown, which has"a supply conduit I2 connectedto a tank I4 and which is connected to a suitable four-way directionalvalve I6 by means of a pump delivery conduit I8. A conduit 20 connectsvalve I6 to the head end of a motor 22 having a piston 24 to which isconnected a piston rod. 26, and a conduit 28 connects valve I6 to therod end of motor 22. A return conduit 30 connects valve I6 to the inletport 32 of a now-regulating valve 34. An outlet port 36 of valve 34 isconnected to tank I4 by means of a conduit 38.

Incorporated in the pump delivery conduit I8 is a suitable relief valve40 which is preferably constructed in accordance with the disclosure ofthe patent to Harry F. Vickers, No. 2,043,453. Valves of this charactermay be provided with a trol valve 42 is connected by means of a conduit44 to a venting port 46 of valve 48, and a conduit 48 connects valve 42with tank I4. An exhaust conduit 50 connects valve 40 to tank I4. In oneposition, valve 42 will close venting port 46 vand direct fluid frompump I to valve I6 which will direct it to motor 22 to start said motor,while, in another position, valve 42 will open venting port 46 to tankI4 by means of conduits 44 and 48, permitting valve 40 to opencompletely and unload pumpy I0 to tank I4 by means of the exhaustconduit 50, thus stopping motor 22. Belief valve 40 serves as a safetyvfactor in limiting the maximum pressure attainable in the system andwill relieve to tank I4 any amount of iluid from pump I0 in excess ofwhich valve 34 is originally adjusted to pass.

Valve 34 is comprised of a body 52 having a main longitudinal steppedbore 54 in which is tightly inserted a sleeve 56. Sleeve 56 has alongitudinal stepped bore 58 which is in communication with an inletpassage 60 by means of a passage 62 and a groove `64. Another 'passage66 and a groove 68 of sleeve 56 form 9, means of communication betweenbore 5B and a passage in body 52. A passage 12 forms a. means ofcommunication between passage 10 and an outlet passage 14 which is incommunication with outlet port 36. y l

Rotatably mounted in a -bore 16, which intersects passages 10 and 12, isan adjustable throttle valve 18 which serves as an adjustablerestriction to flow from passage 10 to passage 12.

Shiftable within bore 58 of sleeve 56 and bore 54 of body 52 is acompensating valve 80 comprised of a hollow piston 82 to which isconnected a stem 84 having a land 86 immediately to the right of piston-82 and a land 88 spaced apart from land 86 at the extreme right end ofstem 84. Stem 84 is provided with a stepped bore forming a passage 89extending the complete length of the stem to the base of piston 82. A

spring 90 located in a chamber 92 inbore 54, bel

tween piston 82 and an end cap 54 threaded into the left end of bore 54,abuts piston82 and normally positions valve 8|) to the position shown. Asleeve 86 having a, hollow portion forming a :chamber 98 is inserted inthe right end of bore 58'of sleeve 56. A spring |00 of predeterminedtension is located in a. chamber |02 formed in bore 58 between aflangel|04 of sleeve 96 and a shoulder I 06 of sleeve 56. A plug |08, threadedinto the right end of bore 54, originally positions sleeve 96V to theposition shown. l

YA passage I I0 connects inlet passage 60 with a chamber ||2 formed inbore 54 between plug |08 and the left end of sleeve 96. A restrictedpassage II4 in sleeve 96 forms a means of communication between chamber|02 and chamber 98. Land 88 of valve 80 is shiftable within chamber 98of sleeve 56. Sleeve 96 blocks communi cationbetween inlet lpassage 60and an inlet chamber |I5 formed in bore 58 of sleeve 56 between lands 86and 88 of valve 80. Ports I I6 in sleeve 96 form a means ofcommunication between inletpassage 66 and inlet chamber II5 when sleeve96 has shifted sufficiently to the left, with leftward movement ofsleeve 96 being limited by a. shoulder II8 of sleeve I56. A chamber |20formed in bore 54 between piston 82 of valve `be constant.

4 and sleeve 56 is in communication with groove 68 by means of a drilledpassage |22. Passage 12 is in communication with chamber 92 by means ofa. branch passage |24.

The inlet and outlet ports 32 and 36 are preferably located at the backof the body 52 and arranged for connection to the circuit lines bysuitable "panel mounting connections such, for example, as are describedin the Martin Patent No. 2,204,507.

In operation, with the electric motor running and operating pump I0 andwith motor 22 stopped by reason of valve 40 being vented to tank I4, ifvalve 42 is shifted to close venting port 46 of valve 40 and if valve I6is shifted to connect conduit I8 to conduit 29 and conduit 28 to conduit30, fluid under pressure from pump I0 will be delivered to the head endof motor 22.

Discharging fluid from the rod end of motor 22 enters conduit 28, valveI6 and conduit 30 to the inlet port 32 of valve 34. Fluid entering inletport 32 enters inlet passage 60 and is prevented from entering inletchamber I I5 by sleeve 96 ond flows by means of passage IIO to chamber||2 where it reacts against the right end of sleeve 96.

Althoughflud in the hollow portion 96 of sleeve 96 has'a free outlet totank I4 by means of the stepped bore l89 in the compensating valve 89,chamber |20, passage |22, passage 66, groove 68, passage 10, throttle18, passage 12, outlet passage 14. outlet port 36 and conduit 38, fluidin chamber |62 isrestricted by means of passage II4. Passage |I4,because of its size, forms a restriction which provides a dashpotreaction for the movement of sleeve 96 to the left.

- When sleeve 96 has shifted suiiiciently to cause passage ||6 of sleeve96 to break over passage 62 of sleeve 56, fluid from inlet passage 60 isstill blocked from communication with inlet chamber II5 by reason ofland 88. The continual but gradual 'shifting of sleeve 96 finally causespassage II6 of sleeve 96 to break over land 88, thus permitting uid frominlet passage 60 to flow into inlet chamber I|5 from whence it flows totank I4 by means of passage 66, groove 68, passage 16, throttle 18,passage 12, outlet passage 14, outlet port 38 and conduit 38.

The purpose and function of compensating valve 86, which is well knownin the prior art, is to maintain a constant pressure drop acrossthrottle 19. If the discharge of fluid from motor 22 is kept at aconstant regulated rate, the speed of piston 24 of motor 22 consequentlywill Compensating valve 86, by maintaining constant the pressuredifference between the pressure in inlet chamber II5 and the pressure inoutlet passage 12, will maintain the flow across throttle 18at aconstant regulated rate according to the original adjustment of throttle18.

When passage I I6 of sleeve 96 has shifted suiiiciently so as to notonly pass over passage 62 of sleeve 56, but also has broken over land 88of valve 86, the rst amount of ilow from inlet passage 60 will be small.Fluid entering inlet chamber ||5 and flowing to tank I4 also enterschamber |20 by means of passage 66, groove 68 and passage |22 so thatthe total pressure present in inlet chamber I I5 is also present inchamber |20. Excess of fluid over the amount which is flowing to motor22 is exhausted to tank I4 by means of relief valve 40. Whateverpressure is existent in passage 12 is also existent in chamber 92 bymeans of passage |24 where it may act against the left side of piston 82and cause the compensating valve to be truly responsive to the pressuredrop across the throttle 18.

As sleeve 86 continues to shift to the left so as to permit a graduallyincreasing flow of fluid from inlet passage 88 to flow into inletchamber I I and across throttle 18, a point will be reached where thepressure will increase in inlet cham- Y ber II5 and consequently chamber|28 because of the restriction offered by throttle 18. When the pressuredrop is equal to or slightly exceeds the setting of spring 98, thispressure increase which is present in chamber |28 causes piston 82 toshift to the left and partially close passage I|6 ,in sleeve 98, whichis now in continual communication with passage 82 because of thepresence of fluid pressure in chamber ||2 from the discharging end ofmotor 22. Land 88 closes passage ||6 to a degree permitting -just enoughfluid to enter inlet chamber IIS to maintain constant the pressure dropacross throttle 18.

If a sufficient amount of fluid does not enter inlet chamber |I5 tomaintain a pressure drop equal to the resistance of spring 98, spring 98will shiftcompensating valve 88 to the right, causing land 88 to openpassage IIB more fully to allow more fluid to enter inlet chamber II5 tomaintain constant the flow across throttle 18.

Upon completion of the movement of piston 24 of motor 22, if Iit isdesired to shift piston 24 in the opposite direction, valve I6 isshifted to connect conduit I8 to conduit 28 and conduit 20 to conduit 38which permits fluid under pressure from pump I8 to enter the rod end ofmotor 22, and, as in the previous operation, discharging fluid nowmaking an exit from the head end of motor 22 will be controlled byflow-regulating valve 34 in the same manner.

Upon completion of the movement of piston 24 in any direction, if pumpI8 is unloaded or if motor 22 is stopped during a movement oi piston 24by venting valve 48 to tank I4 so as to interrupt the flow of fluidthrough flow-regulating valve 34, spring |88 will shift sleeve 36 to theright. Consequently, when Amotor 22 is restarted and the flow tonow-regulating valve 34 is resumed, the same operational process isrepeated. If it were not for sleeve 36, when motor 22 is stopped andflow through flow-regulating valve 34 is interrupted, compensating valve88 would move to the fully open position by reason of spring 98.

When motor 22 is restarted so as to resume the flow of fluid from thedischarging end of motor 22 through flow-regulating valve 84, due to thefact that compensating valve 88 would be in the fully open position, atemporary flow -of fluid more than the amount of fluid whichflow-regulating valve 34 is originally adjustedl to pass would flow totank I4, and piston 24 of motor 22 would move faster for a shortdistance than should be permitted. This is so because, in normalregulating position, compensating valve 88 is never wholly open orwholly closed but always in'a partially open or closed position so as topermit just` enough iluid'to flow across throttle 18 to maintainconstant the pressure in inlet chamber I I5. Sleeve 96, by temporarilypreventing a flow of fluid through a compensating valve that wouldordinarily be in the fully open position and then gradually permittingan increasing amount of fluid from the discharging end of motor 22 toflow to tank I4, but always in an amount less than the amount thatflow-regulating valve 34 would permit to pass if compensating valve 88was in a regulating position when motor 22 was started. thus 'amountwhich flow-regulating valve 34 is originally adjusted to pass to bedischarged from the motor 22 through the fully open compensating valvewhen a controlled speed movement of the motor is resumed afterinterruption.

It should also be noted that, once flow to the flow-regulating valve 34has been resumed and sleeve 96 has shifted completely, it will be heldin this position by fluid from the discharging endy of motor 22 and willnot in any way interfere with the normal operation of compensating valve88.

While the form of embodiment of the invention as herein disclosedconstitutes a preferred form, it is to be understood that other formsmight be adopted, all coming within the scope of the claims whichfollow.

What is claimed is as follows:

1. A flow regulating valve for controlling flow in hydraulic powertransmission systems comprising in combination means forming a flowpassage having an inlet and an outlet, an adjustable throttle in thepassage, a pressure compensating valve biased to a position fullyopening the passage when flow to the inlet of the passage is interruptedand including operating means responsive to the pressures ahead of andbeyond the throttle for causing the compensating valve to maintain aconstant pressure drop across the throttle. resiliently loaded means inthe passage ahead of the compensating valve and biased to a position fortemporarily closing the passage when 2. A flow regulating valve forcontrolling flow in hydraulic power transmission systems compris- A ingin combination means forming a flow passage' '-1, having an inlet and anoutlet, an adjustable 'f' throttle in the passage, a pressurecompensating valve biased to a position fully opening the passage whenflow to the inlet of the passage is interrupted and including operatingmeans responsive to the pressures ahead of and beyond the throttle forcausing the compensating valve to maintain a constant pressure dropacross the throttle, a resiliently loadedsleeve surrounding thecompensating valve and including means for opening and closing thepassage, said sleeve being biased to a position for closing the passagewhen fluid flow to the inlet of the passage is interrupted, andoperating means for the sleeve responsive to predetermined increases ofpressure at the inlet of the passage when fluid flow is resumed to thepassage after interruption for causing the sleeve gevaar? at a regulatedrate and a pressure compensating valve, operating means for thecompensating valve responsive to the pressure drop across the throttleand causing the compensating valve to assume various regulatingpositions to maintain the pressure drop across the throttle constant andincluding biasing means which normally tend to move the compensatingvalve to the fully open position when now to the passageis interrupted,reslliently loaded means biased to a position closing the flow passageahead of the compensating valve lor preventing ilow through the fullyopen compensating valve when iluld iiow is resumed to the passage afterinterruption, and operating means for the resiliently loaded meansresponsive to pressure increases in the ilow passage ahead of thecompensating valve when iiuid ilow is resumed to the passage afterinterruption gradually opening the passage. l

4. A ilow regulating valve for controlling ilow in hydraulic powertransmission systems comprising in combination means forming a i'lowpassage, in series in said passage an adjustable throttle through whichfluid is adapted to flow at a regulated rate and a pressure compensatingvalve. operating means for the compensating valve responsive to thepressure drop across the throttle and causing the compensating valve toassume various regulating positions to maintain the pressure drop acrossthe throttle constant and including biasing means which normally tend tomove the compensating valve to the fully open position when flow to thepassage is interrupted, a resiliently loaded sleeve for controlling saidpassage ahead of the compensating valve including means for closing andopening the passage, said sleeve being biased to a position closing thepassage when now to the passage is interrupted, and operating means forthe sleeve responsive to pressure increases in the passage ahead oi' thecompensating valve when iiow is resumed to the passage afterinterruption for causing the sleeve to gradually open the passage.

5. A flow regulating valve lor controlling flow in hydraulic powertransmission systems comprising in combination means forming-a ilowpassage having an inlet and an outlet, in series in said passage anadjustable throttle through which fluid is adapted to ilow at aregulated rate and a pressure compensating valve. operating means forthe compensating valve responsive to the pressure drop across thethrottle and causing the compensating valve to assume various regulatingpositions to maintain the pressure drop across the throttle constant andincluding biasing means which normally tend to move the compensatingvalve to the fully open position when ilow to the inlet of the passageis interrupted, resiliently loaded means biased to a position closingthe;

iiow passage ahead oi the compensating valve for preventing iiow throughthe fully open compen- 6. In a hydraulic power transmission systemhaving a iluid pump, a iiuid motor, and control means for selectivelyoperating the motor and interrupting iluid flow to the motor forstopping the same, a flow regulating valve for controlling the speed-oithe motor comprising in combination means forming a ilow passageconnected to the motor, in series in the passage an adjustable throttlethrough which iluid is adapted to iiow at a regulated rate and apressure compensating' valve, means for operating the compensating valveresponsive to the pressure drop across the throttle and causing thecompensating valve to assume various regulating positions to maintainthe pressure drop across the throttle constant and including resilientmeans biasing the compensating valve to the fully open position when`flow to the passage is interrupted, a resiliently loaded sleevesurrounding the compensating valve including means for opening andclosing the passage, saidsleeve being biased to a position closing thepassage when the motor is stopped and lilow to the flow passage isinterrupted, and means for operating the sleeve responsive topredetermined increases in pressure in the passage ahead of thecompensating valve when fluid ilow is resumed to the passage afterinterruption for causing the sleeve to gradually open the passage.

7. In a hydraulic power transmission system having a fluid pump, a iluidmotor. and control means for selectively operating ,the motor andinterrupting tluid ilow to the motor for stopping the same, a ilowregulating valve for controlling the speed of the motor comprising incombination means forming a flow passage connected to the motor, inseries in the passage an adjustable throttle through which iluid isadapted to flow at a regulated rate and a pressure compensating valve,means for operating the compensating valve responsive to the pressuredrop across the throttle and causing the compensating valve to assumevarious regulating positions to maintain the pressure drop across thethrottle constant and including resilient means biasing the compensatingvalve to the fully open position when ilow to the passage isinterrupted, resiliently loaded means biased to a position closing theflow passage ahead of the compensating valve for temporarily preventingilow through the compensating valve when iluid flow to the flowregulating valve is resumed after interruption, and operating means forthe resiliently loaded means responsive to predetermined pressureincreases in the ilow passage ahead of the compensating valve when fluidilow is resumed to the flow passage after interruption for graduallyopening the ilow` passage.

' AMBROSE L. BUSSON.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,985,443 Clute Dec. 25, 19342,166,940 Conradson July 25, 1939 2,313,056 Emerson et al. Mar. 9, 1943

